Credible sources? if by that you mean something like: Treatise on Naval Armaments of the 18th century' or something, no. I got what I know from reading, same as almost everyone else. When I do read, bar shot is usually shown as being fired when the intent is demastation, and chain shot when the intent is just sail destruction. Just because a ship has chain and bar does not mean that they have too much of a different purpose. Do you have any credible sources for saying that